all: ast walker for marking unused fns

.github/workflows/ci.yml

@@ -254,7 +254,7 @@ jobs:
           ## sudo apt-get install --quiet -y libsdl2-dev libsdl2-ttf-dev libsdl2-mixer-dev libsdl2-image-dev
       - name: Build V
         run: make -j4 && ./v -cc gcc -cg -cflags -Werror -o v cmd/v
-      - name: Valgrind
+      - name: Valgrind v.c
         run: valgrind --error-exitcode=1 ./v -o v.c cmd/v
       - name: Run sanitizers
         run: |